Photosensitive resin compositions, which are developable with an aqueous developing solution, comprising a water-soluble aromatic azide compound having a sulfonic acid radical and a binder resin have a wide variety of uses including printing applications such as offset printing, screen printing, and proof printing; electronic material applications such as color filters, block matrices, and printed circuits; and immobilization of biocatalysts.
Aromatic azide compounds having a sulfonic acid radical, which have heretofore been used, include sulfonic acids, and alkali or ammonium salts thereof, typically represented by the following formulas. ##STR4## wherein, A indicates H, Na, K, or NH4.
However, sodium, potassium, or ammonium salt of 4,4'-diazidostilbene-2,2'-disulfonic acid as one of the above photosensitive agents has problems in that it is less soluble in polar solvents such as water, alcohol, cellosolve, dimethylformamide, dioxane, or mixtures thereof, is less compatible with binder resins and, on water developing, undergoes considerable swelling which impairs resolution.
Furthermore, of compounds represented by the above general formulas, sulfonic acids (in which A=H) are highly soluble, but are strongly acidic and, when used for metallic substrates, corrode the metals or require a corrosion-resistant coating, which largely limits their applications.
The alkali metal salts of such acids have problems in that the solubility changes with the pH value of the solution or with crystal configuration. Moreover, these salts cannot be used for electronic materials.